On Aug. 17, 1959 the earth around Yellowstone shook. At 11:37 p.m. a 7.3 magnitude earthquake devastated Hebgen Lake, Montana, located in Yellowstone’s northwestern region—in comparison, the 2010 earthquake in Haiti registered at a 7.0 magnitude.

Resulting Landslide Killed 28 People and formed Quake Lake

The quake caused massive damage, including 28 fatalities and a considerable $11 million in repairs to highways and timbers. Comparably, recent small quakes in Yellowstone (also called an “earthquake swarm”) registered at 0.6 to 3.6 on the Richter scale.

Joann Smith, who was 11 years old at the time of the disaster, recalled the horror of the event for a 50th anniversary article for the Denver Post published Aug. 17, 2009.

“It was frightening. It was horrible,” she said. “You could actually see the ground open up.”

Smith’s recollections aren’t exaggerated. The United States Geological Survey calls the earthquake the worst on record in Montana (records date back to 1869). At the time, it was the second worst earthquake to occur in the lower 48 states.

The event caused a massive avalanche of rock, soil and trees (an estimated 28-33 million cubic meters of material), which descended down from the Madison River Canyon’s south wall at nearly 100 mph. It took less than one minute for the 80 million tons of rock to slam into the narrow canyon, blocking the river and creating Earthquake Lake.

“The shaking and the noise was horrific,” John Owen, then 15, told the Post. “It was just way louder than thunder — just one of the loudest noises I’ve ever heard in my life.”

The fallen material formed a wall blocking the Madison River’s flow. After only three weeks the damned river created a lake more than 170 feet deep.

Overall, massive devastation wreaked havoc on much of the area. The summer houses stationed along Hebgen Lake sustained shifted foundations, crumbled chimneys and burst pipelines. Roads cracked and shifted, and three of the five reinforced bridges located near the quake’s center were severely damaged. Large portions of nearby forests were destroyed.

The lake the quake created covers an area five miles long and 1/3 of a mile wide. Nowadays, fishermen enjoy scouring the 190-foot depths for cutthroat and brown trout, which are stocked yearly. Those looking to cast a line will have the most success with dry fly fishing as the many timbers below the surface make float tube fishing frustrating.

Quake Lake Visitor Center

Today, tourists to the area can stop by the Earthquake Lake Visitor Center, which is situated 27 miles north of West Yellowstone on US Highway 287, to experience the horror Smith and Owen recall. Here, visitors will find interpretive displays on earthquakes, plate tectonics and a functional seismograph, in addition to the a stunning panoramic view of the mountain that fell. The center’s observatory features movies and talks that regale the audience with stories of the earthquake. The Memorial Boulder, a remnant of the earthquake, has a plaque engraved with the names of all 28 people who died during the event.

The Earthquake Lake Visitor Center is open daily from 10am to 6pm from Memorial through mid-September, although exact dates vary on the year. Call for more information or to check schedule: